Activated inorganic bleaches



United States Patent 5 Claims. 61. 8-111) ABSTRACT OF THE DISCLOSUREBleaching process for textile fibers employing a peroxidic bleachingbath activated with an acylated phosphonic acid ester or an acylatedphosphinic acid which contains at least one organic group bound directlyto the phosphorus atom through a carbon atom and solid peroxidicbleaching compositions containing such activators.

The present invention relates to an improved process for the treatmentof natural and synthetic textile fibers, either as such or in the formof yarns, woven and knitted fabrics or articles produced therefrom, withaqueous baths containing peroxidic bleaching compounds and moreparticularly with such baths containing novel activating agents andcompositions suitable for the preparation of such activated baths.

It is known that peroxidic compounds, such as hydrogen peroxide, sodiumperoxide, sodium per-borate, sodium percarbonate, sodium perphosphateand the like, can be used in washing and bleaching baths for textilefibers of all types. However, in some instances certain difiicultiesoccur in their use as relatively high temperatures must be employed ifthe desired bleaching action is to be achieved. As a rule, temperaturesalmost up to boiling are used for such Washing or bleaching. Such hightemperatures 'for the washing and bleaching baths require considerableheat energy and furthermore are not suited for the ordinary Washingmachine.

For these reasons various so-called activators have been proposed whichwill permit the Washing and bleaching operations to be carried out atlower temperatures while still achieving the desired whitening effectand good spot removal. Examples of such activators, for example, are:tormamide, amides of unsaturated lower carboxylic acids, organicnitriles, anhydrides of diand poly-basic carboxylic acids, as well asanhydrides of unsaturated carboxylic acids.

Furthermore, according to US. Patent 3,073,666, acetylated alkylphosphate esters are useful activators to inorganic penoxidic bleaches,

According to the invention it has now been found that acylatedphosphonic acid esters or acylated phosphinic acids, that is, compoundsWhich contain organic groups lbou'nd directly to the phosphorus atomthrough a carbon atom and not through an intermediate oxygen atom, aregood activators for inorganic per-oxidic bleaching agents. Illustrativeexamples of such acylated phosphonic acid esters or acylated phosphinicacids are as follows:

Acylated phosphonic acid esters Acylated phosphinic acids As indicated,the organic groups directly connected to the phosphorus atom through acarbon atom such as alkyl or aryl groups may carry sub-stituents.

The novel activators according to the invention, depending upon theircomposition, are liquid or solid and easily or difficultly soluble inwater. The quantities of such activators required are relatively smalland as a rule 0.1 to 1 mol of the activator per mol of active oxygen inthe bleaching bath suflices.

Usual stabilizers, buffers, Wetting agents, detergents, protectiveagents for fibers and/or optical brighteners may also be added to theactivated bleaching baths according to the invention.

The best action according to the invention is obtained in neutral,weakly acidic or weakly alkaline baths or, in other words, at a pHbetween about 3 and 11. The active oxygen content of such bathspreferably is between 0.05 g. and 20 g. per liter.

The presence of the activators according to the invention in thebleaching baths causes a bleaching action to take place at relativelylow temperatures. For example, bleaching actions which can only beachieved at temperatures between 70 and C. in the absence of activatorscan be attained in the presence of the activators at temperaturesbetween 30 and 60 C.

It furthermore was found that mixtures of solid inorganic peroxidicbleaching compounds with activator compounds according to the inventionwhich are solid as Well as with the other usual components of washingagents are stable at normal temperatures and therefore can be stored ina form ready for use in preparation of the aqueous activated bleachingbaths.

The following examples will serve to illustrate the invention withreference to several embodiments thereof.

Example 1 A rayon staple fiber woven fabric 'was boiled in red wine anddried. The white content thereof when measured with aZeiss-Elrepho-whiteness degree measurer against white standard 56-5 withfilter 6 was 31%.

The strongly soiled fabric was washed 3 times for minutes at 60 C. in aLaunder-O-Meter (Atlas) with an aqueous bath which per liter containedthe following:

G. Lauryl sulfate 1.250 Sodium pyrophosphate 0.625 Sodiumtripolyphosphate 0.625 Dry water glass 0.350 Sodium perborate 1 0.700O-benzoyl-phenyl phosphonic acid ethyl ester 1.000

The pH of the bath was 7-8. After such wash the fabric had a 64.3% whitecontent.

In comparison, when the soiled fabric was given a washing treatmentunder 'the same conditions with the same bath composition except for theomission of the O-benzoyl-phenyl phosphonic acid ethyl ester its whitecontent was only raised to 44.5%.

Example 2 A red wine soiled cotton woven fabric with a white content of26% was washed 3 times for 15 minutes at 60 C. as in Example 1 with anaqueous bath which per liter contained the following:

G. Lauryl sulfate 1.250 Sodium pyrophosphate 0.625 Sodiumtripolyphosphate 0.625 Dry water glass 0.350 Sodium perborate 0.700

O-benzoyl-phenyl phosphonic acid phenyl ester 1.000

Example 3 A rayon staple fiber woven fabric was boiled in red wine for 1hour and dried. The strongly soiled fabric which had a white content waswashed three times for 15 minutes at 60 C. as in Example 1 with anaqueous bath which per liter contained the following:

G. Lauryl sulfate 1.250 Sodium pyrophosphate 0.625 Sodiumtripolyphosphate 0.625 Dry water glass 0.350 Sodium perborate 0.700

O-benzoyl-styryl phosphonic acid phenyl ester 1.000

After such wash the fabric had a 57.2% white content. t

In comparison, when the soiled fabric was given a washing treatmentunder the same conditions with the same bath composition except for theomission of the O-benzoyl-styryl phosphonic acid phenyl ester its whitecontent was only raised to 47.2%.

The increase in whiteness content caused by the presence of theactivator therefore was 10.0% steps.

' Example 4 A rayon staple fiber woven fabric was boiled in red Wine for1 hour and dried. The strongly soiled fabric which had a 28.0% whitecontent was washed three times for 15 minutes at 60 C. as in Example 1with an aqueous bath which per liter contained the following:

G. Lauryl sulfate 1.250 Sodium pyrophosphate 0.625 Sodiumtripolyphosphate 0.625 Dry water glass 0.350 Sodium perborate 0.700O-benzoyl-diphenyl phosphinic acid 1.000

Example 5 A rayon staple fiber woven fabric was boiled in red wine for 1hour and dried. The strongly soiled fabric which had a 28.0% whitecontent was washed three times for 15 minutes at 60 C. as in Example 1with an aqueous bath which per liter contained the following:

G. Lauryl sulfate 1.250 Sodium pyrophosphate 0.625 Sodium'tripolyphosphate 0.625 Dry water glass 0.350 Sodium perborate 0.700O-benzoyl-di-n'butyl phosphinic acid 1.000

After such wash the fabric had a 57.8% white content.

In comparison, when the soiled fabric was given a washing treatmentunder the same conditions with the same bath composition except for theomission of the O-benzoyl-di-n-butyl phosphinic acid its white contentwas only raised to 38.6%.

The increase in whiteness content caused by the presence of theactivator therefore was 19.2% steps.

We claim:

1. In a process for the treatment of fibers with an aqueous bathcontaining an inorganic peroxidic bleaching agent, the step whichcomprises incorporating a sufiicient amount of a compound selected fromthe group consisting of acylated phosphonic acid esters andO-benzoylphenyl phosphonic acid ethyl ester, O-benzoyl-chlorophenylphosphonic acid ethyl ester, O-benzoyl-phenyl phosphonic acid phenylester, O-benzoyl-chlorophenyl phosphonic acid phenyl ester,O-benzoyl-styryl phosphonic acid phenyl ester, O-benzoyl-diphenylphosphinic acid and O-benzoyl-di-n-butyl phosphinic acid in such bath toactivate said bleaching agent.

2. The process of claim 1 in which 0.1 to 1.0 mol of said compound isincorporated in said bath per mol of active peroxidic oxygen.

3. The process of claim 1 in which the temperature of said bath isbetween 30 and 60 C.

4. A solid activated peroxidic bleaching composition consistingessentially of a solid inorganic peroxidic bleaching agent and 0.1 molof a solid compound selected from the group consisting ofO-benzoyl-phenyl phosphonic acid ethyl ester, O-benzoyl-chlorophenylphos- 5 6 phonic acid ethyl ester, O-benzoyl-phenyl phosphonicReferences Cited acid phenyl ester, O-benzoyl-chlorophenyl phosphonicUNITED STATES PATENTS acid phenyl ester, O-benzoyl-styryl phosphonicacid phen yl ester, O-benzoyl-diphenyl phosphinic acid and O-beu-$003910 10/199 mthmar 252 99 XR zoyl-di-n-butyl phosphinic acid. i 53073666 1/1903 Dlthmar 8 111 3,122,417 2/1964 Blaser et a1 252186 XR 5.The solid activated perovidic bleaching composition of claim 4 in whichthe quantity of said solid compound is 0.1 to 1.0 mol per mol of activeoxygen in said LEON ROSDOL Puma]? Examiner peroxidic bleaching agent. M.WEINBLATT, Assistant Examiner.

